JP2927339B2 - High temperature electrochemical battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention
An electrode material having the function of a pole and having such an electrode
The present invention relates to a high-temperature electrochemical cell. [0002] BACKGROUND OF THE INVENTION Problems to be solved by the invention
Part of calcium ion or strontium
・ High lanthanum manganite modified by ion substitution
Used as electrode material for hot solid electrolyte fuel cells
You. Part of the lantern is replaced with calcium ions or
Lanthanum chromite modified by substitution with rontium ion
The air electrode or air in a high temperature solid electrolyte fuel cell
It is considered as a material that is also used as an electrode and a support. this
Each type of fuel cell has a support, an air electrode, an electrolyte,
Fuel electrode, interconnects and other continuous functions
It consists of a bonding layer of a ceramic material. Manufacturing or motion
During the heating cycle between high temperature and room temperature during operation, the fuel cell
To prevent damage to the fuel cells.
Desirably, the expansion characteristics are consistent. Thermal expansion of each layer
If the properties do not match, the layer will crack during thermal cycling.
Fuel cell malfunction or at least low efficiency
May fall. [0003] Modified lanthanum manganite and modified chromate
Difficulties in manufacturing fuel cells using lanthanum oxalate
Is a material of this type that has been modified to have the highest electrical conductivity.
The coefficient of thermal expansion of the stabilized zirconia electrolyte or stabilized
Commonly used in the manufacture of fuel cells such as zirconia supports
Is greater than the coefficient of thermal expansion of some other materials
That is. The thermal expansion coefficients of these various materials are specific
Depends on composition selected for use in various fuel cells
Is the heat of lanthanum manganate and chromite
Adjust expansion coefficient to match thermal expansion coefficient of other materials
It is strongly hoped that we can do it. Thus, the coefficient of thermal expansion is
The above materials can be used in fuel cells
And may cause cracks in battery members during thermal cycling.
Absent. [0004] According to the present invention, there is provided the following general formula:
Against gas by a compound consisting of a solid solution represented by
Formed in the form of a porous tube, La1_-xw(M_L)_x(Ce)_w(M_s1)_1-y(M_s2)_yO_Three Where M_L Is at least one of Ca, Sr and Ba;
_s1Is Mn or Cr or Mn and Cr; M_s2Is N
i, Fe, Co, Ti, Al, In, Sn, Mg, Y,
At least one of Nb and Ta; w is 0.05 to 0.2
5; x + w is 0.1 to 0.7; y is 0 to 0.5 and solubility
The density of the solid solution is about 80% of the theoretical density
The function of the support tube and the electrode, which does not exceed
Provide a combined member. [0005] The present invention further provides an electrode bonded to an electrolyte.
Is a compound consisting of a solid solution represented by the following general formula
Is formed,       La_1-xw(M_L)_x(Ce)_w(M_s1)_1-y(M_s2)_yO₃ Where M_LIs at least one of Ca, Sr and Ba;
_s1Is Mn or Cr or Mn and Cr; M_s2Is
Ni, Fe, Co, Ti, Al, In, Sn, Mg,
At least one of Y, Nb, and Ta;
25; x + w is 0.1 to 0.7; y is 0 to 0.5
Within the limits of solubility; the electrode is
Provided is an electrochemical cell serving as a mechanical support for each member of a pond.
You. The modified lanthanum manganite or modified zinc oxide
Part of lanthanum in lanthanum romate replaced with cerium
Then, the coefficient of thermal expansion decreases, and the support tube and
Well with the coefficients of thermal expansion of other materials used in the electrolyte
It was found that they would be matched. Cerium is
14 rare earth elements with similarities in many aspects of their biological properties
Of the present inventor despite only one of
According to experiments, at almost the same concentration, only cerium
Modified lanthanum chromite and modified lanthanum manganite
Has such a large effect on the thermal expansion coefficient of
Was a surprising finding. Small amount of lanthanum in cerium
Substitution with increases the resistivity slightly, but increases the resistivity.
Large enough to be extremely useful as an air electrode material
Stop every time. In order that the present invention may be more clearly understood,
Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
explain about. [0008] DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG.
Support tube 2 that provides structural stability or structural strength to the pond
Having. Generally, the support tube is a gas permeable
Is calcia stabilized zirconia forming a porous wall?
And its thickness is about 1-2 mm. Support tube
2 has a thin porous air electrode, ie, cathode 3,
Surrounding. Cathode 3 is generally used for plasma melting.
Spraying or slurry spraying or dipping and baking in slurry
Attached to the support tube by well-known techniques such as knotting
From about 15-1000 microns thick composite oxide
Be composed. This air electrode is used for lanthanum manganate or
Or chemically modified oxidation containing lanthanum chromite
Or a mixture of oxides or oxides. On the electrode
Some parts are typically zirconia stabilized with yttria.
Airtight solid consisting of about 1-100 microns thick
An electrolyte is provided. The length selected in the electrolyte attachment process
A mask is applied to the hand-direction section 5, but this section 5
The interconnect material 6 is deposited to form the interconnect 6. Interconnect
The material is conductive in oxygen and fuel atmospheres.
There must be. Interconnects should be 5-100 mm thick
Clon, generally calcium, strontium, etc.
Or magnesium-doped lanthanum chromite
Become. Areas other than battery interconnects serve as anodes
It is surrounded by a working fuel electrode 7. Typically
The thickness of the anode is 30-100 microns. Mutual connection
A material 8 having the same composition as the anode adheres to the upper part of the connecting portion 6
doing. A typical example of this material 8 is nickel-silyl
Konia cermet or cobalt zirconia sir
Met, 50-100 microns thick. In operation, such as hydrogen or carbon monoxide,
A gaseous fuel that flows outside the cell as a source of oxygen
Pass inside the battery. Oxygen is introduced at the interface with the electrode.
On and oxygen ions pass through the electrolyte to the anode
Go to The electrons are collected at the cathode and are
Current flows in the road. One battery interconnect
By contacting the anode of multiple batteries,
Can be connected in series. This type of fuel cell
No. 4,395,468 and US Pat.
No. 3,400,054 and November 20, 1982
U.S. Patent Application No. 323,641 filed on Feb.
Person: Isenberg)
I want to. [0010] The ceramic of the present invention is a bevelskite.
Has a crystal structure similar to that of
Is a solid solution: La_1-xw(M_L)_x(Ce)_w(M_s1)_1-y(M_s2)_yO_Three M in the formula_L Are calcium, strontium, barium
Or a mixture of these, but because they are inexpensive, 100
% Calcium, preferably a solid oxide fuel cell.
It has been found that the operating characteristics in the pond are good. the above
The presence of these ions improves the conductivity. M in the formula_s1
Is manganese, chromium or a mixture thereof;
_s2Is nickel, iron, cobalt, titanium, aluminum
, Indium, tin, magnesium, yttrium, d
Obium, tantalum, or a mixture thereof. formula
Where y is 0-0.5, preferably 0,
Or addition of components other than chromium is generally not preferred.
No. Manganese is used in the compound because of its conductivity.
To make it better. The presence of chromium in the compound
Chromium is more electrolyte than manganese
Does not react with In addition, each of the above-mentioned elements
Do not add more than the limit of resolution. The value of x + w is 0.
1 to 0.7, preferably 0.4 to 0.7, and x + w is
If it is less than the above range, the conductivity is reduced, and exceeds the above range.
Causes the thermal expansion behavior of ceramics to deteriorate and cause a phase change
Possibilities arise. The value of w is preferably 0.05 to 0.25,
0.1 to 0.2, and the value of w is less than the above range.
The thermal expansion coefficient of the ceramic decreases significantly,
Exceeding the enclosure will cause the conductivity to drop,
(ZrO_Two)_0.85(CaO)_0.15Stabilizing di like
To match the range of the coefficient of thermal expansion of the luconia material
It is not necessary for the value of w to exceed the above range. Some of the materials with good thermal expansion coefficients
Has been experimentally confirmed, but these materials
Can crack during thermal cycling even if they are joined together.
It is known to be less steep. Such a combination
As an example, (ZrO_Two)_0.9(Y_TwoO_Three)
_0.1Using as electrode material La_0.3Ca_0.5-0.6Ce_0.2-0.1MnO_Three Can be used. Another example
As (ZrO)_Two)_0.85(CaO)
_0.15To the electrode La_0.3Ca_0.5-0.6Ce_0.2-0.1MnO_Three Can be used. In another example,
As an electrolyte (ZrO_Two)_0.9(Y_TwoO_Three)_0.1make use of, La_0.3Ca_0.5-0.6Ce_0.2-0.1CrO_Three In combination with an electrode consisting of Yet another example is the support
As a carrier or electrolyte (ZrO_Two)_0.85(CaO)_0.15
Using, La_0.3Ca_0.5-0.6Ce_0.2-0.1CrO_Three It is an example of combining with an electrode composed of: Modified lanthanum manganite or modified magnesium
Lanthanum lomate is a single-phase solid solution and consists of two phases.
It is not a mechanical mixture. Ceramics according to the present invention
Is to mix the compounds of each element in the required specific ratio,
Press and sinter at 400 ° C to 1800 ° C for 1 to 4 hours
It can be manufactured by Compounds that can be used are oxidation
Oxides by heating such as oxides, carbides and oxalates
Are compounds that form Solid electrolyte electrochemical cell
Combination of support tube and electrode, ie support tube
To be used as a single member that combines the functions of
Select the particle size and sintering temperature to determine the density of the sintered oxide.
Should not exceed about 80% of the theoretical density.
The boundary between the electrode and the electrolyte where electrochemical reaction occurs through the body
Make the density reachable to the surface. For example, fuel cells, electrolyzers
Or solid electrolyte electrochemical such as oxygen gauge
The above-mentioned lanthanum chromite can be used in applications other than batteries
Thermal expansion coefficient between electrode members of MHD generator by solid solution
It can be more closely matched. Next, the present invention will be illustrated by way of examples. Embodiment Compound MnO_Two, Cr_TwoO_Three, La_TwoO_Three, CaCO_Three, Sr
CO_Three, CeO_TwoAnd Y _TwoO_ThreeAnd use each compound in the required ratio
Mixed at a rate of 70.3-703kg / cm^Two (1000-10
000 psi) followed by sintering for 1 to 4 hours.
_0.3Ca_0.5Ce_0.2MnO_Three, La_0.7Sr_0.3MnO_Three,
La_0.7Sr_0.2Ca_0.1MnO_Three, La_0.35Ca_0.65Mn
O_Three, La_0.5Ca_0.5CrO_Three, La_0.3Ca_0.5Ce_0.2
CrO_ThreeWas prepared. The composition containing manganese is 14
Sintered between 00 ° C and 1500 ° C and contains chromium
The composition was sintered at about 1600 ° C. Thermal expansion data
For comparison, (ZrO_Two)_0.92(Y_TwoO_Three) 0.08 sintering
I prepared a stick. The product is approximately 2.54 cm long (1 inch
H), width and thickness 0.635 cm x 0.635 cm (1 /
4 inch x 1/4 inch). Rod shape
135 to stabilize the coefficient of thermal expansion.
The thermal cycle between 0 ° C and room temperature was repeated three times. Thereafter, the temperature is raised to increase the expansion coefficient of the rod.
It was measured. 2 and 3 show the results. In FIG.
A is La_0.5Ca_0.5CrO_ThreeAnd B is (ZrO_Two)
_0.92(Y_TwoO_Three)_0.08And C is La_0.3Ca_0.5Ce
_0.2CrO_ThreeIt is. 2 and 3 contain cerium.
Compounds having a cerium-free analog
Better match with yttria-stabilized zirconium than
It has the following thermal expansion characteristics. [0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic explanatory view showing a cross section of a fuel cell. FIG. 2 is a graph showing a thermal expansion characteristic of a ceramic according to the present invention. FIG. 3 is a graph showing a thermal expansion characteristic of a ceramic according to the present invention. [Description of Signs] 1 fuel cell 2 support tube 3 air electrode (cathode) 4 solid electrolyte 7 fuel cell (anode)

Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01M 4/86 H01M 4/86 T 4/90 4/90 X

Claims (1)

(57) [Claims] It is formed in the shape of the porous tube to gases by a compound consisting of a solid solution represented by the following general _{formula, La 1-x-w (} M L) x (Ce) w (M s1) 1-y (M _s2) in _y O ₃ formula, _{M L} is Ca, at least one of Sr and Ba; M
_s1 is Mn or Cr or Mn and Cr; _Ms2 is Ni, Fe, Co, Ti, Al, In, Sn, Mg,
At least one of Y, Nb, and Ta;
25; x + w is 0.1 to 0.7; y is 0 to 0.5 and within the limit of solubility; the support tube and the electrode, characterized in that the density of the solid solution does not exceed about 80% of the theoretical density A member that combines the functions of 2. Electrode joined to the electrolyte is formed by compounds consisting of a solid solution represented by the following general _{formula, La 1-x-w (} M L) x (Ce) w (M s1) 1-y (M s2) y O ₃ wherein at least one of _{M L} is Ca, Sr and Ba; M
_s1 is Mn or Cr or Mn and Cr; _Ms2 is Ni, Fe, Co, Ti, Al, In, Sn, Mg,
At least one of Y, Nb, and Ta;
25; x + w is 0.1 to 0.7; y is 0 to 0.5 and within the limit of solubility; The electrochemical cell in which the electrode serves as a mechanical support for another battery member, that is, each member of the battery .